1. Field of the Invention
The present invention relates to a toner replenishing apparatus for replenishing toner to a developing section for developing an electrostatic image on a surface of a photoreceptor with the toner, and an image forming apparatus including the toner replenishing apparatus.
2. Description of the Related Art
In a toner replenishment method in an image forming apparatus in which an electrostatic image on a surface of a photoreceptor is developed with toner to form an image on a recording medium, a toner replenishing container is firstly filled with the toner. Then, the toner filled in the toner replenishing container is replenished to a toner hopper and is supplied from the toner hopper to the electrostatic image on the surface of the photoreceptor. In the case of such an image forming apparatus, when a user thereof tills the toner replenishing container with the toner, there is a problem that a toner filling work tends to be troublesome since the toner sometimes adheres to a user's hand to soil it, and so on.
In order to solve such a problem, recently, a method has become a mainstream, in which method, when the toner to be supplied to the electrostatic image on the surface of the photoreceptor becomes insufficient, it is determined that the toner in the toner replenishing container is exhausted and the toner replenishing container itself is replaced with a new one, but in such a toner replenishing container, sometimes, the toner particles are aggregated to one another and get solidified due to the weight of the toner itself, resulting in that the toner may not be able to be replenished smoothly to the toner hopper and thus, there is a problem that it is impossible to completely use the toner in the toner replenishing container.
In order to prevent the toner particles in such a toner replenishing container from being aggregated to one another, a rotary toner replenishing container is practically in use, in which, with the toner replenishing container itself rotating, the toner is guided and transported by a spiral projection formed on an inner surface of the toner replenishing container and then replenished to the toner hopper. Such a rotary toner replenishing container is able to suppress aggregation of the toner in the toner replenishing container with the simple structure. However, the rotary toner replenishing container has a problem that the toner in the toner replenishing container adheres to the inner wall of the toner replenishing container and remains undischarged from the toner replenishing container.
For coping with such a problem, for example, Japanese Unexamined Patent Publication JP-A 2000-147887 discloses a rotary toner replenishing container provided with a spiral scraping member that rotates along an inner wall of the rotary toner replenishing container to scrape off toner adhering to the inner wall.
However, in the toner replenishing container disclosed in JP-A 2000-147887, when there remains a large quantity of toner in the toner replenishing container, frictional resistance between the spiral scraping member and the toner is so large that a drive torque required for rotating the toner replenishing container is also large, thereby a problem is posed that wear of driving components for the toner replenishing container and the scraping member itself are rapidly progressed.